JP3697556B2 - Vehicle braking device - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a vehicle braking device that performs automatic braking during traveling of an automobile, and more particularly to a vehicle braking device that prohibits useless braking operation when decelerating during normal traveling.
[0002]
[Prior art]
As a conventional technique of this type of vehicle braking device, a technique described in Japanese Patent Publication No. 4-25182 can be cited.
[0003]
When the technology described in the above publication is below the safe distance of the inter-vehicle distance, this is reported to the driver as an alarm, and the actual braking pressure is not sufficient to maintain the safe distance even if the driver steps on the brake petal The braking operation is performed up to the target braking pressure so that the necessary safety distance can be maintained.
[0004]
Japanese Patent Publication No. 5-42861 discloses a braking device that applies a braking force after the driver starts the accelerator pedal release operation until the driver starts to depress the brake pedal.
[0005]
[Problems to be solved by the invention]
However, the technique described in the above Japanese Patent Laid-Open No. 4-25182 is a braking operation which automatically enters a braking operation when the safety distance is less than the inter-vehicle distance, and is not expected by the driver. When braking is applied, the braking feeling does not match. In other words, it is a time when the driver is not expected to determine whether the inter-vehicle distance is less than the safe distance, and there is a sense of discomfort because it is not linked to the driver's intention.
[0006]
In Japanese Patent Laid-Open No. 5-42861, since the driver applies a braking force between the start of the accelerator pedal release operation and the depression of the brake pedal, unnecessary braking is performed. , The probability of deterioration of fuel consumption increases.
[0007]
Therefore, an object of the present invention is to provide a vehicle braking device that reads a driver's intention to decelerate and accurately decelerates without reflecting useless braking reflecting the driver's intention.
[0008]
[Means for Solving the Problems]
The vehicle braking device according to claim 1 is an object distance sensor that obtains an inter-vehicle distance to a front object, a vehicle speed sensor that obtains a current vehicle speed, and an accelerator pedal that is operated by a driver who obtains the depression pressure of an accelerator pedal. An accelerator opening sensor for detecting the stepping pressure of the vehicle, the control device obtains an ideal target inter-vehicle distance from the current vehicle speed by the vehicle speed sensor, obtains the current inter-vehicle distance from the object distance sensor, A current target deceleration is calculated from the target inter-vehicle distance; a current deceleration is calculated from the current vehicle speed; a brake control amount is calculated by subtracting the current deceleration from the target deceleration; and enter the accelerator opening corresponding to the depression amount of an accelerator pedal operated by the driver by the accelerator opening sensor, the accelerator depression speed is smaller than a predetermined threshold value When the accelerator opening is smaller than a predetermined threshold value, and outputs the brake control amount by the brake actuator.
[0009]
According to a second aspect of the present invention, there is provided a vehicle braking apparatus comprising: an object distance sensor that obtains an inter-vehicle distance to an object ahead; a vehicle speed sensor that obtains a current vehicle speed; and an accelerator pedal that is operated by a driver who obtains the depression pressure of an accelerator pedal. A throttle opening sensor for detecting the stepping pressure of the vehicle, the control device obtains an ideal target inter-vehicle distance from the current vehicle speed by the vehicle speed sensor, obtains the current inter-vehicle distance from the object distance sensor, A current target deceleration is calculated from the target inter-vehicle distance; a current deceleration is calculated from the current vehicle speed; a brake control amount is calculated by subtracting the current deceleration from the target deceleration; and The throttle opening according to the depression amount of the accelerator pedal operated by the driver by the throttle opening sensor is input, and the accelerator depression speed is lower than a predetermined threshold value. Saika, when the throttle opening is smaller than a predetermined threshold value, and outputs the brake control amount by the brake actuator.
[0010]
[Action]
In the first and second aspects , the relative speed with respect to the object in front of the vehicle and the distance therebetween are detected by the detecting means, and the release of the pedal pressure of the accelerator petal is detected by the stepping pressure detecting means. When the relative speed with respect to the object in front of the vehicle is greater than or equal to a predetermined value, or when the distance from the object in front of the vehicle has decreased to a predetermined value or less, the step pressure detection means is When the release is detected, the brake is operated by the braking drive means so as to be in a predetermined deceleration state.
[0011]
【Example】
Hereinafter, a vehicle braking apparatus according to an embodiment of the present invention will be described.
[0012]
FIG. 1 is a block diagram showing the overall configuration of a vehicle braking apparatus according to an embodiment of the present invention.
[0013]
In the figure, an object distance sensor 1 comprises a radar such as a microwave that measures the distance to a front object, and the distance to the object ahead of the vehicle according to the arrival time of the reflected wave of the emitted microwave. Is to measure. The vehicle speed sensor 2 is a known speed sensor that detects the running state of the vehicle. The accelerator opening sensor 3 detects the depression pressure of the accelerator pedal and detects the accelerator opening corresponding to the depression amount. The outputs of the object distance sensor 1, the vehicle speed sensor 2, and the accelerator opening sensor 3 are input to the control device 4. The control device 4 is composed of a microcomputer or the like. The control device 4 outputs the brake actuator 5 that operates the brake and the buzzer 6 that outputs an alarm sound. The brake actuator 5 is publicly known, and is described in, for example, Japanese Patent Laid-Open Nos. 61-175130 and 5-85349, so that detailed description thereof is omitted.
[0014]
In the control device 4, program control is performed as follows.
[0015]
FIG. 2 is a flowchart of a program showing the control of the vehicle braking device of one embodiment of the present invention.
[0016]
First, in step S1, vehicle speed calculation is performed to obtain the current vehicle speed V. In step S2, the deceleration G = −d / dt · V is calculated from the change in the vehicle speed V from the vehicle speed sensor 2. In step S3, the target vehicle distance is determined based on the relationship map between the current vehicle speed V and the target vehicle distance Lt stored in the internal ROM. Lt is detected. The target inter-vehicle distance Lt is calculated by using the current vehicle speed V. Lt = CL1 ・ V + CL2
May be obtained by performing an operation as follows. However, CL1 and CL2 are constants.
[0017]
Next, in step S4, the inter-vehicle distance L to the front object is measured by the object distance sensor 1, and in step S5, the target deceleration Gt is calculated using the target inter-vehicle distance Lt. That is, the target deceleration Gt is set to Gt = C1 (Lt-L)
Calculate as However, C1 is a constant.
[0018]
In step S6, the brake control amount B is calculated based on the target deceleration Gt. Brake control amount B is
B = C2 (Gt -G)
Calculate as However, C2 is a constant.
[0019]
In step S7, the accelerator pedal depression pressure of the accelerator pedal is detected by the accelerator opening sensor 3, and the accelerator opening Th corresponding to the depression amount is detected. In step S8, the accelerator opening degree Th is differentiated to obtain the accelerator depression speed Dth as Dth = d / dt · Th.
Calculate as
[0020]
In step S9, it is determined whether the accelerator depressing speed Dth is smaller than a predetermined threshold Cd1 and in a direction to release the depression, and in step S10, the accelerator opening degree Th is smaller than a predetermined threshold Ct1, and the accelerator is opened. When the accelerator depression speed Dth is smaller than a predetermined threshold value Cd1 or when the accelerator opening degree Th is smaller than a predetermined threshold value Ct1, a brake permission flag is determined in step S13. Stand up. In step S11, it is determined whether the accelerator depression speed Dth is greater than a predetermined threshold value Cd2 and is in the direction of depressing acceleration. In step S12, the accelerator opening degree Th is greater than a predetermined threshold value Ct2, and the accelerator opening degree is determined. When the accelerator depression speed Dth is larger than a predetermined threshold value Cd2 or when the accelerator opening degree Th is larger than a predetermined threshold value Ct2, a brake permission flag is set in step S14. take down.
[0021]
After the processing of step S9 to step S14, it is determined whether the brake permission flag is set in step S15. When the brake permission flag is off, the routine returns to the routine processing from step S1, and the brake permission flag is set in step S15. When it is determined that the brake is in operation, the brake of the brake control amount B calculated in step S6 is set in the operating state in step S16, and the process returns to the routine from step S1.
[0022]
It should be noted that the buzzer 6 can be sounded when the brake of the brake control amount B is set in the operating state in step S16. Of course, a lamp display (not shown) may be used. At this time, the driver can be informed of the operating state of the device, and the brake can be fed back accurately to the driver in the operating state of the brake.
[0023]
Here, the process of the brake control amount executed in the routine of steps S1 to S8 will be described with reference to the control system.
[0024]
FIG. 3 is a block diagram of a control system showing the control of the brake control amount of the vehicle braking system of one embodiment of the present invention.
[0025]
In FIG. 3, the current vehicle speed V is inputted by the vehicle speed sensor 2, the relationship between the current vehicle speed V and the target inter-vehicle distance Lt is selected by the map 11, and the target inter-vehicle distance Lt is obtained as the selection output, and the subtraction circuit. 12, the inter-vehicle distance L to the front object obtained by the object distance sensor 1 is subtracted from the target inter-vehicle distance Lt, and the target deceleration Gt is calculated by the multiplication circuit 13 as Gt = C1 (Lt−L).
[0026]
On the other hand, the vehicle speed V is input to the differentiating circuit 14 and differentiated by the differentiating circuit 14 to calculate the deceleration G = −d / dt · V, and the subtracting circuit 15 reduces the output from the target deceleration Gt of the multiplying circuit 13. The speed G = −d / dt · V is subtracted, and the multiplication circuit 16 calculates the brake control amount B as B = C2 (Gt−G).
[0027]
Further, the accelerator stepping process executed in the routine of steps S9 to S14 will be described with reference to the control system.
[0028]
FIG. 4 is a block diagram of a control system showing processing of accelerator depression conditions of the vehicle braking system of one embodiment of the present invention.
[0029]
In FIG. 4, the accelerator pedal pressure is detected by the accelerator opening sensor 3, the accelerator opening Th according to the amount of depression is input, differentiated by the differentiation circuit 17 to obtain the depression speed, and the accelerator depression speed is obtained by the threshold circuit 18. When Dth is smaller than a predetermined threshold Cd1 or the accelerator opening degree Th is smaller than a predetermined threshold Ct1 in the threshold circuit 19, the R / S flip-flop 20 is set via the OR gate 21 and a brake permission signal is output. To do.
[0030]
In addition, the accelerator pedal depression pressure is detected by the accelerator opening sensor 3, the accelerator opening Th according to the depression amount is input, differentiated by the differentiation circuit 17 to obtain the depression speed, and the accelerator depression speed Dth is obtained by the threshold circuit 23. When the threshold value Cd2 is larger than the predetermined threshold value Cd2 or the accelerator opening degree Th is larger than the predetermined threshold value Ct2 in the threshold circuit 24, the R / S flip-flop 20 is reset via the OR gate 22 and the brake permission signal is negated.
[0031]
As described above, in the vehicle braking apparatus of the present embodiment, the object distance sensor 1 that obtains the inter-vehicle distance to the object ahead, the vehicle speed sensor 2 that obtains the current vehicle speed, and the accelerator opening that obtains the depression pressure of the accelerator pedal. And the control device 4 obtains the ideal target inter-vehicle distance Lt from the current vehicle speed V by the vehicle speed sensor 2 and the current inter-vehicle distance L from the object distance sensor 1 to obtain the target inter-vehicle distance. The current target deceleration Gt is calculated from the distance Lt, the current deceleration G is calculated from the vehicle speed V, and the brake control amount B is calculated by subtracting the current deceleration G from the target deceleration Gt. The accelerator opening degree Th corresponding to the accelerator pedal depression amount is input by the accelerator opening sensor 3, and the accelerator depression speed Dth is smaller than a predetermined threshold value Cd1, or the accelerator opening degree Th is lower than the predetermined threshold value Ct1. Is smaller, it outputs a brake control amount B by a brake actuator 5.
[0032]
That is, the current vehicle speed V is obtained by the vehicle speed sensor 2, the relationship between the vehicle speed V and the ideal target inter-vehicle distance Lt is obtained, and the inter-vehicle distance L to the front object is obtained by the object distance sensor 1. Get. Further, the target deceleration Gt is obtained from the target inter-vehicle distance Lt and the inter-vehicle distance L, the current deceleration G is calculated from the vehicle speed V, and the current deceleration G is subtracted from the target deceleration Gt, whereby the brake control amount B is obtained. Calculate.
[0033]
On the other hand, the depression amount of the accelerator pedal is detected by the accelerator opening degree sensor 3, and the accelerator opening degree Th corresponding to the depression amount is inputted, and the accelerator depression speed Dth is smaller than a predetermined threshold Cd1 or the accelerator opening degree Th is predetermined. When the value is smaller than the threshold value Ct1, the brake permission signal is output and the brake control amount B is output by the brake actuator 5. In addition, the accelerator pedal depression pressure is detected by the accelerator opening sensor 3, and the accelerator opening Th corresponding to the depression amount is input, and the accelerator depression speed Dth is greater than a predetermined threshold Cd2, or the accelerator opening Th is When it is larger than the predetermined threshold value Ct2, the brake permission signal is denied and the operation of the brake actuator 5 is not started.
[0034]
Therefore, it is possible to read the driver's intention to decelerate with the accelerator opening sensor 3 and to perform an accurate deceleration without applying unnecessary braking reflecting the driver's intention. Therefore, the control is linked to the driver's intention, and the control without causing the driver to feel strange is possible. Further, since the brake operation is not simply started when the driver starts the accelerator pedal release operation, there is no possibility that unnecessary braking is performed or fuel consumption is not deteriorated.
[0035]
In particular, in this embodiment, when the accelerator depression speed Dth is smaller than the predetermined threshold Cd1, it is determined when the accelerator opening degree Th is smaller than the predetermined threshold Ct1, and the accelerator depression speed Dth is larger than the predetermined threshold Cd2. When the accelerator opening degree Th is larger than the predetermined threshold value Ct2, the threshold value is different and a hysteresis is provided between the two, so there is a dead zone of the vehicle braking device. There is no possibility of chattering and the operation is stable.
[0036]
By the way, although the object distance sensor 1 for obtaining the inter-vehicle distance to the object in front of the above embodiment has been described as the radar using the microwave, when the present invention is implemented, the object in front What is necessary is just to obtain an inter-vehicle distance to an object, and since there is a high possibility that a front object is usually a vehicle, it can be a sensor that detects a vehicle traveling forward.
[0037]
Further, the accelerator opening sensor that obtains the depression pressure of the accelerator pedal in the above embodiment may detect the depression amount of the accelerator pedal, or may detect the opening of the throttle as a throttle opening sensor.
[0038]
【The invention's effect】
As described above, in the vehicle braking device according to claim 1 , the object distance sensor that obtains the inter-vehicle distance to the object ahead, the vehicle speed sensor that obtains the current vehicle speed, and the accelerator opening that obtains the depression pressure of the accelerator pedal. An ideal target inter-vehicle distance is obtained from the current vehicle speed by the vehicle speed sensor, the current inter-vehicle distance is obtained from the object distance sensor, and the current target deceleration is obtained from the target inter-vehicle distance. Further, the current deceleration is calculated from the current vehicle speed, the brake control amount is calculated by subtracting the current deceleration from the target deceleration, and the accelerator opening is detected by the accelerator opening sensor. When the accelerator depressing speed is smaller than the predetermined threshold value or the accelerator opening is smaller than the predetermined threshold value, the brake control amount is output by the brake actuator. Is shall.
[0039]
Accordingly, the driver's intention to decelerate can be read by the accelerator opening sensor, and the vehicle can be decelerated accurately without applying unnecessary braking reflecting the driver's intention. Therefore, the control is linked to the driver's intention, and the control without causing the driver to feel strange is possible. Further, since the brake operation is not simply started when the driver starts the accelerator pedal release operation, there is no possibility that unnecessary braking is performed or fuel consumption is not deteriorated.
[0040]
According to a second aspect of the present invention, there is provided an object distance sensor that obtains an inter-vehicle distance to an object ahead, a vehicle speed sensor that obtains a current vehicle speed, and a throttle opening sensor that obtains a depression pressure of an accelerator pedal. And an ideal target inter-vehicle distance is obtained from the current vehicle speed by the vehicle speed sensor, the current inter-vehicle distance is obtained from the object distance sensor, and the current target deceleration is calculated from the target inter-vehicle distance. Further, the current deceleration is calculated from the current vehicle speed, the brake control amount is calculated by subtracting the current deceleration from the target deceleration, and the throttle opening is input by the throttle opening sensor. When the accelerator depressing speed is smaller than a predetermined threshold or the throttle opening is smaller than a predetermined threshold, a brake control amount is output by the brake actuator. Is shall.
[0041]
Therefore, the driver's intention to decelerate can be read by the throttle opening sensor, and the vehicle can be decelerated accurately without applying unnecessary braking reflecting the driver's intention. Therefore, the control is linked to the driver's intention, and the control without causing the driver to feel strange is possible. Further, since the brake operation is not simply started when the driver starts the accelerator pedal release operation, there is no possibility that unnecessary braking is performed or fuel consumption is not deteriorated.
[Brief description of the drawings]
FIG. 1 is an overall configuration block diagram of a vehicle braking apparatus according to an embodiment of the present invention.
FIG. 2 is a flowchart of a program showing control of a vehicle braking device according to an embodiment of the present invention.
FIG. 3 is a block diagram of a control system showing the control of the brake control amount of the vehicle braking device of one embodiment of the present invention.
FIG. 4 is a block diagram of a control system showing processing of accelerator depression conditions of the vehicle braking system of one embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Object distance sensor 2 Vehicle speed sensor 3 Accelerator opening sensor 4 Control apparatus 5 Brake actuator

Claims (2)

An object distance sensor for obtaining a distance between the vehicle and a front object;
A vehicle speed sensor to obtain the current vehicle speed,
An accelerator opening sensor for detecting the depression pressure of the accelerator pedal operated by the driver who obtains the depression pressure of the accelerator pedal ;
An ideal target inter-vehicle distance is obtained from the current vehicle speed by the vehicle speed sensor, a current inter-vehicle distance is obtained from the object distance sensor, a current target deceleration is calculated from the target inter-vehicle distance, and the current vehicle speed is calculated. The brake deceleration is calculated by subtracting the current deceleration from the target deceleration, and the amount of depression of the accelerator pedal operated by the driver by the accelerator opening sensor. And a control device that outputs a brake control amount by a brake actuator when the accelerator depression speed is smaller than a predetermined threshold or the accelerator opening is smaller than a predetermined threshold. Vehicle braking device. An object distance sensor for obtaining a distance between vehicles to the object in front;
A vehicle speed sensor to obtain the current vehicle speed,
A throttle opening sensor for detecting the depression pressure of the accelerator pedal operated by the driver who obtains the depression pressure of the accelerator pedal;
An ideal target inter-vehicle distance is obtained from the current vehicle speed by the vehicle speed sensor, a current inter-vehicle distance is obtained from the object distance sensor, a current target deceleration is calculated from the target inter-vehicle distance, and the current vehicle speed is calculated. The brake control amount is calculated by calculating the current deceleration from the vehicle, subtracting the current deceleration from the target deceleration, and according to the accelerator pedal depression amount operated by the driver by the throttle opening sensor. A control device for inputting a throttle opening and outputting a brake control amount by a brake actuator when the accelerator depression speed is lower than a predetermined threshold or when the throttle opening is lower than a predetermined threshold;
A vehicle braking device comprising:

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